Ignition magnetos fob internal



IGNITION MAGNETOS FOR INTERNAL-COMBUSTION ENGINES Filed Nov. 10, 1943 INVENTOR. MST 4 a. flww A TTORNEY Patented Sept. 25, 1945 IGNITION MAGNETOS FOR INTERNAL- COMBUSTION ENGINES John Archibald Baines, Willesden Junction, Lon- .don, England, assignor to Rota: Limited, London, England Application November 10, 1943, Serial No. 509,805 In Great Britain November 3, 1942 9 Claims. (01. 171-209) v This invention relates to ignition magnetos for internal combustion engines. of the kind comprising the combination of a generator, a distributor, and an interrupter, the distributor being situated between the generator and the interrupter. The interrupter comprises a rotary cam driven by the generator spindle, and one or more contact levers pivotally mounted on a support adjacent to the cam. In a magneto of this kind the distributor is contained in a compartment of the casing which is bounded at one side by the generator and at the other side by another'compartment containing the interrupter and any other component of the apparatus that may be required to be housed in this compartment. To gain access to the distributor for inspection or repair it is necessary to remove the compartment containing the interrupter. In some constructions this operation is troublesome and involves risk of disturbance of the adjustment of the interrupter. The object of the present invention is to provide an improved construction enabling the compartment containing the interrupter to be detached in a convenient manner.

The invention comprises the combination of a plate forming the whole or a part of an end wall of the distributor compartment, a bearing or bearings formed or mounted on the plate, a rotary cam carried by the bearing" or bearings and adapted to supportand'to be slidably connected with the adjacent end of the generator spindle, and a contact lever or levers and contacts mounted on the plate adjacent to the cam.

In the accompanying sheet of explanatory drawings Figures 1 and 2 are respectively a part sectional side elevation and a part sectional end elevation of a magneto embodying the invention.

Figure 3 is a sectional side elevation of a modifled feature of the invention.

a The casing of the magneto shown in Figures l. and 2, is constructed from separable parts which form three compartments, namely, two end compartments a, b and an intermediate compartment 0. In the end compartment a are arranged the components of the generator, for example, a stationary permanent magnet or magnets, a stationary winding or windings in which electric currents can be generated, and an inductor rotor ponents of the distributor whereby (when the magneto is in use) high tension discharges are delivered in the desired sequence to the sparking plugs of the engine. The rotary part of the distributor is carried on the rotor spindle d 0! the generator. In the other end compartment b are arranged the components of the interrupter, and any other components such as for example, a cooling fan. The portion of the casing forming the compartment 1; comprises a removable plate e which serves as the whole or a part of the end wall of the distributor compartment, and a removable end cover f which encloses the interrupter compartments, the removable plate being .formed with a peripheral flange g to which the removable cover is secured.

In carrying the invention into effect as shown in Figures 1 and 2, I form or provide on the plate 2 a bearing or bearings h coaxial with the rotor spindle d, this hearing or bearings being preferably of the ball or roller type. Carried by the bearing or bearings h is a short hollow spindle i on the outer end of which is formed or secured the interrupter cam g. This hollow spindle i is held against axial movement relatively to the bearing or bearings h by a collar is on the inner end of the spindle, or by other means. The outer face of the cam i may have secured to it the cooling fan abovermentioned, this fan being indicated by m. The hollow cam spindle i is arranged in axially slidable spline connection with the adjacent end of the rotor spindle d, and serves to support this end of the rotor spindle. Preferably and as shown a spring n is arranged in a bore 0 in the end of the rotor spindle d carrying the hollow spindle i, this spring serving by abutting against the rear side of the fan m to take up any endwise slackness in the rotor spindle.

Also on the plate e and adjacent to the cam is or are mounted a contact lever or levers p and contacts q operable by the cam for controlling the electrical circuit or circuits associated with the generator. 4

The arrangement above described is such that to gain access to the distributor components it is only necessary to detach from the casing the plate e carrying the interrupter (with or without previous detachment of the above-mentioned end cover f). In this operation the cam spindle 5 comes away from the rotor spindle d with the plate e and the relationship between the cam 7' and contact lever or levers p is undisturbed. Replacement of the plate e is effected equally simply, the cam spindle i in this action being slid into re-engagement with the adjacent end of the rotor spindle d.

Instead of the hollow cam spindle above described, I may employ a solid cam spindle 12 as shown in Figure 3, in which case the rotor spindle d is of hollow form, the cam spindle being slidably splined in and adapted to support the otherwise unsupported adjacent end of the rotor spin= die. In this example the cam spindle i is supported by a single bearing 71, on the plate c and constructional details may be varied to meet different requirements.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. An ignition magneto generator comprising a distributor compartment containinga generator spindle, a plate forming at least a part of a wall of the distributor compartment, at least one bearing on the plate, a rotary cam carried by the bearing and adapted to support and to be slidably connected with the adjacent end of the generator spindle, and at least one contact lever and contacts mounted on the plate adjacent to the cam.

2. An ignition magneto generator as claimed in claim 1 and having in combination a spindle on one end of which the cam is provided and which is supported by the bearing, and means whereby the cam spindle is held against axial movement relatively to the bearing, the cam spindle being adapted to be slidably connected to the adjacent end of the generator spindle.

3. In apparatus of the class described, a casing, a plate removably secured across an opening in said casing, a driving shaft rotatably journalled in said casing, a stub shaft rotatably mounted through said plate and removable therewith, cooperable means on said shafts for automatically drivably connecting the same when said plate is secured to said casing, cam means on said stub shaft, and circuit breaker means mounted on said plate for direct operation by said cam means.

4. In ignition apparatus of the class described, a supporting plate adapted to be removably seassaeve cured to a casing, a bearing in said plate, a cam shaft through said plate rotatably supported in said bearing and held against movement relative thereto independently 01' said casing, and circuit breaker contacts mounted on said plate for operation by said cam, said plate, bearing, cam and contacts being removable from said casing as a unit.

5. In apparatus of the class described, an ignition circuit breaker unit comprising a supporting plate adapted to be removably mounted in a casing, a cam mounted on a shaft extending through said plate independently of said casing for rotation relative thereto, and a pair of engagable contacts mounted on said plate, at least one of said contacts being movable by said cam during rotation of the latter.

6. In apparatus ofthe class described, an ignition circuit breaker unit comprising a supporting plate adapted to be removably mounted in a casing', a cam shaft mounted through said plate independently of said casing for rotation relative thereto, a pair of engagable contacts mounted on saidgplate, at least one of said contacts being movable by said cam during rotation of the latter, and means on said cam shaft for detachably coupling the same with a rotatable driving member mounted in said casing. v

7. In apparatus of the class described comprising a casing and a driving shaft rotatably Journalled in said casing, the combination therewith of a supporting plate detachably secured ,to said casing, a stub shaft mounted through said plate for rotation relative thereto in axial alignment with said driving shaft, cam means on-said stub shaft, circuit breaker contacts mounted on said plate and operable by said cam, and cooperable means on said shafts for drivably connecting the same whenever said plate is secured in position on said casing.

8. Apparatus as defined in claim 7 wherein resilient means are interposed between said driving shaft and said stub shaft for resisting relative axial movement of said shafts.

9. An ignition magneto generator having a circuit breaker unit consisting essentially of a rotatable cam-bearing spindle supported in a bearing carried by a removable wall of a casing, a generator spindle adapted to make a telescoping connection with and to be supported by the cam spindle, and electrical contacts mounted on said removable wall in position for direct operation by 

